We take ELECTRA-large [1]} as the backbone of our proposed framework and the single-hop QA model, and train a single-hop question generator using BART-large [2]}.
The weights to balance losses are chosen as \(\lambda _1 = 10/5\)  (for HotpotQA/2WikiMultiHopQA), \(\lambda _2 = 2\)  and \(\lambda _3 = 5\) . The maximum value of required reasoning hops is set as \(K=2\)  for HotpotQA and \(K=4\)  for 2WikiMultiHopQA. More training details are given in Appendix .
